Vacuum booster-brake-control valve



L. w, SHUT-rs VACUUM BOOSTER BRAKE CONTROL VALVE Filed March 26, 1928--Patented I'Ieb. 4,"1930i u t UNITED sTATEs PATENT oFF-ice;

' LEROY w. snur'rs, on nnrnoir, insmeren, AssreNoa 'ro' GENERAL moronsBE- snaacn conrom'rron, or nnrarr, M1cHIeAN, CORPORATION or nnrawanr.-

. vacuum BoosTEreBnAxE-confrnot vALvE Appli-cation filed March 26,A1928.A Serial No. 261,932.`

This inventionrelates to `an improved brake applyingl mechanism and tothat type wherein the manual effort exerted by the operator issupplemented by. an auxiliary brake applying means, preferably a sourceof fluid pressure.

Such systems are known and areparticularly useful on motorl vehicleswhere brakes must frequentlybeforcibly applied land where a source ofiuid pressure is readily available as-an auxiliary source 'of power; thesuction 1 of the engine of themotor vehicle being frequently used forthis purpose. In such systems there have been associated a powercylinderand a valve,.the latter operated by the pedal in its movements,andwhich valve comprises movable arts functioningat tim'es to withdrawair Y at other times to admit air to the .power cylinder. Y -4 Thepresent invention is concerned with such known systems. Its object is tosimplify the construction by the avoidance of numerous parts by `whichthe valve is operated. As a further object, the invention provides aconstruction whereby the variable pressures by which the powercylinderoperate's and which pressures are under the control of theoperator also react upon the pedal to give a' feel which shall beindicative to the operator of the intensity of the auxiliary force Aactingto apply the brake. Other objects and advantages will beunderstood from a readlng of the following'descriptien and from anexamination of the accompanying drawing. l In-the Idrawing:

Figure 1 shows in side elevation the novel arrangement constituting myinvention.

' Figurei2 is a transverse section through [the valve membershowing theoperative relation between the pedal andthe brake `hook-up.

.Referring by reference.. characters to 'the drawing, numeral 5 reresents a part of a vehicle frame. Numeral?4 represents a/pedal foractuating a brake located within a housing 9 45 4and operatedby a cam orthe like,'not shown,

.but carried ona shaft 11 having anactuating lever arm' 1.3; Thehousingmay consist-of a drum on a' wheel. and a closure plate carried by theaxle'. 'These features lare conventional 56 and not fully* illustratedsince the specific knected a rod or link 31 extended to a p'oint rom thepower cylinder vand from Vrod 37. This conduit connectspower- 'detailsof the brake are not a part of this;l

invention. v

The pedal is provided with a retracting spring lconnected thereto and toany convenient point on the frame. There lis also provided a fixed stop17 to be engaged by the pedal under the action of the spring 15.'Rigid'withthe pedal is an arm 19 connected by a link or rod 21. The arm13 of the brake actuating means connected by a rod or link 23,'the link23 being connected at its' other end to an arm 25 secured to arock-shaft 27 suitably journaled in the frame. Shaft 27 also carries arigid arm 29 to which is conadjacent the end ofrod 21.

A suitable connection betweenrods 21 and 31 will obviously give amechanical brake application upon pressure beingv applied to the pedalbythe foot of the operator.

At 3311s a -powercylinder having a piston y 35 therein, the piston beingconnected by rod 37 to an arm 39 also mounted on shaft 27 L A conduitdlcommunicates with the cylinder-33 on that side of piston 35 remote 75cylinder33 with a control valvedesignated as .an 'entirety by numeral 43. A conduit communicates with the valve 43 and is to beconnected as'isusual in such cases with the intake manifold of the internal combustion,engine of the vehicle.

In such systems as heretofore arranged, the valve which is thecounterpart Iof valve 43 of thiscase hasbeen usually so, located Le5react on the pedal to give the desired feel 9o Y indicative totheoperator of the work being v done by the power cylinder in brakeapplication. The arrangement of valve mounting to -be now describedavoids vthis plurality of parts and retains'all the functions of the 95valve including the provision for reaction on Vthe pedal.

Rod 21 is integral with or Asecured toa y cover member 51 attached byfastening means 53 to a housing V55, the parts land 55 cen 100stituting4 the valve43. The cover member 51 has secured thereto one endof a sylphon bellows 57 the bellows carrying at its movable end a valveseat 59. 4Within the bellows the cover 51 is formed with a tubularmember 61 extending to a point adjacent the valve seat. 59. The tubularextension 61 is t bevelled off as at 63 to form a valve seat, this beingthe seat for a Valve element 65, the suction valve element ofthe valve43. Within vthe tubular member 61 is a second coaxial of rod 31. Rod 3lhas a sliding connection through a cap 75 threaded upon a reduced end-77 of the housing. 55. Slidable within said reducedv end 77 is ahollowsleeve 79 A closed at one end as at 81. Fastening means -ment wherebythe pedal 83 secure wto said sleeve an automatic valve element 85 shapedto engagethe movable valve seat 59 carried by the free end of thebellows., Sleeve 79 extends to a point somewhat near head 51 and at thatend is formed with a terminal flange 87 against which may;

rest valve 65. Spring 89 encircles sleeve 79 and engages valve elementsand. 85. Rod 31 is inwardly, by engaging its end closure'81. Thisfunctions to `raise air valve 85 fromits seat 59. Rod 31 also hassecured thereto a disk 91 located within the tubular sleeve 79 and nearthe flange 69 ofjextension 67. Between the disk 91 and the end-81ofsleeve 79 is a'coil spring 93. Preferably the closed end 81 of thesleeve 79 will be inwardly extended as shown .in the drawing to make aclose sliding fit with rod 31. It will be observed from the drawing thatcap 75 is outwardly extended as at 95 to provide a space for thereception of abutment 90 as-therod 31 reciprocates outwardly from thevalve chamber. The valve 43 is thus floatingly mounted in a mechanicalconnection between the -pedal 7 and the brake.

This construction simplifies the arrangeoperates'the brake and also thevalve mechanism and'whereby the fluid pressure operating through .thevalvev reacts upon the pedal.

The operation may be briefly described; When the device is at rest the4spring 71 has drawn, rod 31 toits inward limit, this limitfbeinattained when disk 73 engages head 51.` Th as to beheld inl a positionof restwhen .disk 91 engages flange 69.v Under these circumstances,

with 'the result' that. atmospheric valve e ement 85fislifted fromitsseat' 59. The inner end flange' 87 of sleeve- Amoved toward head 51, thespring 89 holding the suction valve element provided with an abutment 90operable to at times move sleeve 79 engine therefore is `amechanicaLpull and a creases'in intensity e parts may also be soarranged f 4practically7 the vabutment 90 will have pushedsleeve79.inward and 65 against its seat 63. With the parts in these relativepositions, the power cylinder 33 is vented to the atmosphere throughconduit 41, through the bellows 57 and through the open valve 85 to anopening 32 in the housing member 55. This opening 32 may, and preferablyis, provided with a conventional air cleaner 34 to prevent dust orforeign matter reaching the seats of thevalves; The pedal may then bedepressed to apply the brake. This movement pulls upon the linkage andtakes up brake shoe clearance. As soon as an ap'.- preciable resistanceexists at the brake there occurs a relative movement between-the link21, together with the valve 43 and the rod 31. The spring 71 iscomparatively stifl so that further dpedal movements move rod 31, 31 toa lesser extent than rodv 21. The extent of movement of rod 31 togetherwith rod 21 amounts to a direct .pull upon the brake. Thev difference inmovement of rods 31 and 21 is accommodated by a compression of spring 71and this difference o f movement functions to introduce the suctionbrake applying means; This relative movement of rod 31 relative toflange 69 also moves disk 91 relative to the sleeve end 81. e abutment90 is moved away from end 81 and the spring 93 operates to move sleeve79 and through its connection with air valve element 85 toseat said airvalve element'.v This same movement if continued causes flange 087 tolift suction valve 65 from its seat 63. Figure of the drawing shows theparts 1n this position. Under these circumstances, popnlly 11s( tltilrea lli'ecl; pull from the pedal o erae rou in 21flan e69s 71 and rod 31,butg the g pnng en accompanied by a movement of compression of spring 79whereby the suction valve is opened. The

I -now drawing air from the power cylinder through the conduits 41 and45, which are in communication through the opem suction valve 65. Therehas been thereforez adivision of giedal effort betweeii orce relativelysmall introducing a sup lementaryo relatively strong fluid pressurerake. t A e pressure in the power cylinder goes down, lthe pressurewithin the bellows also goes down an@ the air pressure within chamber 55outside ellows tends to contract the bellows but 1t does so a aiiistlthe tension in the brake applying li age 21-31. he suction inthe valveeleellows increases and since valve'seat'" 59 is 1 0 anchoredby the,`pull of rod l31 through isk 91 and spring 93, the-sleeve 79 valve85engaging the seat, the collapsing ries the o. her end of the'bellows.This atmospheric pressure will obviously act iii the di` rection. ofarrow LA and will tend. to push the pedal pad up against the footof theop# erator. The greater the suction withinthe bellows, the greaterthis-'reaction 'upon the pedal pad. The valve is therefore of the refaction type .and gives the operator the feel which'measures for him theintensityof the Vsupplemental powerbrake applying force.

As the suction builds up it, sooner or later,

. andif vhe does so, the increment of his presvalve permitting air toflow into` the cylinclosesvalve element 65 maintaininga suctioncondition within the bellows. Thereafter,T the operatormay furtherdepress the pedal sure is divided as before between al direct mechanicaleffort anda. valve opening force, the latter measured by the extent towhich the spring 71 is compressed by this 'ad ditional pedal pressure.Again, the suction builds up and gives, as before, a further pressurereaction upon the'pedal pad. If the operator completely releases thepedal, the suct1on valve closes as the spring 71 restores rod 31 to itsinitial position. The abutment 90 pushes sleeve 79 inwardly and opensthe air der 33. .t

It should be explained that the valve has a -followup action which maybe described as follows:

As'the suction of the engine increases the degree of vacuum withinthe-power cylinder and the bellows in the valve, the 'collapsingyeil'ect ofthe outside air'pressure acting on valve seat 59 causes thevalve element 85 and sleeve 79 to move inwardly along rod 31 comLpressing sprlng 93.-' This movement permits valve element 65 to close onits seat 63, thus' l". shutting oi the suctionof the engine andmaintaining the valve and power cylinder at the degree of vacuumattained up to that time. Thereafter, the operator may further depressvthe pedal again opening valve element 65 and permitting the enginesuction to increase the' degree of vacuum obtained. The increasedpressure diference between the inside and outside of thel bellows willagain compress spring93 and permit the valve element 65 to close.` Thusit may be seen that the degree of vacuum may be 'increased by very smallamounts untilqthe loading on spring 93 is sulicient to hold .the sleeve7 9 and valve seat 59 against the pressure difference caused bythemaximum degree of vacuum obtainable. In such case, the valve elementS15-remains.

open (because the outside air pressure cannot compress 'spring 93further) and the engme suction remains in communication with the power'cylinder -thu's maintaining the maximum braking elect. u I claim:

1. In a mechanical and" power brake operating mechanism, a brake,a'manually operable member, a tension member connected to said brake andmanually operable member,

' said tension member-'including a control device for said power brakeoperating mechanism, said controldevice constructed reactive uponsaidmanually operable member in proportion to the force exerted by saidpower brake operating mechanism.

2. In a mechanical and -power brake ope1-atingmechanism, .a brake, amanually 0perable member, a tension member therebetween and connectedthereto, a power oper.` ated mechanism including a control deviceconcentric with. 'said-tension member, said tension member comprisingparts movable relatively longitudinally, means operated by said relativemovementto .actuate said control device, said control device constructedto react upon saidmanually'operable member-in proportion to the brakeapplying torce ex erted by the power brake operating mechanism.

.3. In combination, a manually member, a memberto be operated thereby, atension member therebetween, a power operated member, a connectionbetween the said power operated member and said member to be operated, acontrol element for said power operated member, .said control elementconstituting a part of's'aid tension member and reactingupon saidmanually operable membe r. l 4. The invention defined by claim 3, saidtension member including parts having arelative longitudinal movement,means constituting' apart of said control element and operated by therelative movement of said relatively movable parts to control said powerdevice, said control. device variably reacting upon `said operatingmeans in proportion to the power exerted by. said power device.

i operable i In a lmechanical and suction operated gether with yieldingmeans between said rela-4 tively movable parts.

7. In combination, a manually operated member, a brake actuating member,a tension member therebetween, a VHuid power operating device, aconnection between said power operating device and'said brake actuatinglerating device associated with said tension member, a conduit `forconnecting said control member and fluid powerdevice, a conduit fromysaid control member for connection vto a` source of suction, saidcontrol member comprising Aa collapsible chamber having openmember, acontrol member for said power opings to said conduits, f said tensionmember no having parts arranged for relative axial movement, meanswhereby said axial movement in'the act of brake application `opens saidconduits throughsaid control member.

5 8.The invention defined by claim 7, Said means includinfir a suctionvalve between said openings, and the separatingmovements of said partsoperable to open said suction valve.

9. The invention defined by claim 7, to-

m gether with means operable upon said axially movable parts uponrelease of the manually operated member to restore normal 'air pressureto' said control member and fluid power u 10. In a mechanical `andvacuum power operated brake, a pedal, a brake,- a tension membertherebetween, said` tension member comprising parts movableVlongitudinally relatively to each other, 'resilient means to resist go'movement of separation of said parts, a housing carried by one of saidparts, a flexible member carried by .said housing', a suction valve seatfxedly'carried by said housing, a movable air valve seat carried by theexible member, an intermediate member within said1 housing and slidablecoaxially thereof, valves .engageable with said seats, one slidable on'the intermediate member and the other secured to the intermediatemember, means associated $0 with said other part ,to move saidintermediatek member and said suction valve when said other part movesaway from said first part, andv other means-associated with said otherpart and operable` upon the opposite move- 85 ment of said other partrelative to the first part to permit the suction valve. to vclose and topositively open the air valve.

11. The invention defined -by claim 10,\said flexible member being asylphon bellows.

o 12. The invention defined by claim 10, said means whereby the otherpart .opens the suction valve comprising a disk secured tol said othervpart and a vspring` between said disk and said intermediate member. i

- 13.- The invention 'defined by claim 10, said i means whereby theother part opens the air valve comprising an-abutment on said other partmovably engaging said intermediate lpart under the return action of theirst-men- 60' tioned resilient means. ,j

14. In combination, a manually operable member, brake means, tensionmeans between and` connected to said member and brake 4means, fluidvpressure brake operating-mecha- 55 nism, a control valve for said fluidpressure brake operatin y mechanism, -lsaid control s valve constitutinga part of said tension means and vreacting under theini'uence ofpressure conditions therewithin upon said 60' manually operablemember.

, In testimony whereof Ivailixvm signature.- LEROYX-W. HUTTS.

